Apparatus for cleaning liquids

ABSTRACT

The invention relates to an apparatus comprising a drum drivable in rotation having a conical jacket wall which is mounted on a fixedly arranged core; supply means for carrying the contaminated liquid into the interior of the drum; discharge means for discharging the heavy contaminants from the part of the drum in the proximity of the largest jacket diameter; an at least substantially cylindrical ceramic filter received in the core; and drainage means arranged in the fixed core for draining the cleaned liquid.

The present invention relates to an apparatus for cleaning contaminatedfluids.

Such apparatus are generally known, for instance in the form of filters,for instance ceramic filters.

Filters, in particular ceramic filters, are suitable for removal fromfluids, for instance liquids, wherein gases are not however excluded, ofmaterials, for instance contaminants, with molecules larger than themolecules of the basic fluid. Through use of a filter with the correctdimensions the basic fluid can pass through the filter while thecontaminants with molecules of larger dimensions are restrained by thefilter.

Cleaning apparatus for fluids are further known which make use ofseparating mechanisms based on mass. An example hereof are centrifuges,wherein contaminants with a higher density or a lower density than thebasic fluid can be separated from the basic fluid. In order to enablecleaning of fluids which are contaminated with contaminants with ahigher density and with contaminants with larger molecular dimensions,two separate devices must be used according to the prior art. Thisresults in costly and complicated apparatus.

DE-A-3305153 provides a single apparatus with which contaminants with ahigher density can be removed as well contaminants with larger moleculardimensions.

DE-A-3405153 discloses an apparatus for cleaning contaminated fluids,comprising a combination of a centrifuge for removal from thecontaminated liquid of contaminants with a specific gravity other thanthe liquid and a filter for removal from the liquid of contaminantswhich have molecules with larger dimensions than the liquid molecules,the combination being integrated into the apparatus, the apparatuscomprising:

a drum drivable in rotation having a conical jacket wall;

supply means for carrying the contaminated liquid into the interior ofthe drum, the supply means comprising a pump for developping thepressure required for the ceramic filter;

discharge means (15, 19, 20) for discharging the heavy contaminants fromthe part of the drum (14, 15, 17, 18) in the proximity of the largestjacket diameter;

an at least substantially cylindrical ceramic filter (6) received in thecore; and

drainage means (11) for draining the cleaned liquid.

In this prior art the ceramic filter relates to substantial forces whichmay cause damage.

As a result of these measures use can be made of a single apparatuswhich can be of compact construction.

It will be apparent that this will result in an attractive solution atmany locations.

In order to remove contaminants with a greater specific gravity, use canbe made of the apparatus as according to a first preferred embodimentwhich comprises:

a drum drivable in rotation having a conical jacket wall which ismounted on a fixedly arranged core;

supply means for carrying the contaminated liquid into the interior ofthe drum;

discharge means for discharging the heavy contaminants from the part ofthe drum in the proximity of the largest jacket diameter;

an at least substantially cylindrical ceramic filter received in thecore; and

drainage means arranged in the fixed core for draining the cleanedliquid.

It will be apparent that it is also possible to provide such anapparatus wherein contaminants with a lower density can be removed. Suchan apparatus will then have to be constructed with the filter on theoutside, which will certainly entail technical problems; such a ceramicfilter will then for instance have to be assembled from segments.

According to another preferred embodiment, the discharge means comprisea moving device for causing the drum jacket and the end wall with thesmaller diameter to move away from the end wall. Causing the drum jacketto move away from the end wall results in a gap between drum jacket andend wall with which the contaminants can be discharged.

According to yet another preferred embodiment, the end wall with thesmaller diameter is mounted on a central, stationary shaft which isdrivable in its lengthwise direction, and the drum jacket and the largerend wall are mutually connected by a connection allowing of an axialmovement.

This results in a structurally advantageous embodiment .

According to yet another preferred embodiment, radially extendingpartitions connected to the jacket are arranged in the drum. Therotating movement of the liquid is hereby enhanced, so that theeffectiveness of the centrifuge action is increased.

According to another preferred embodiment, walls extending substantiallytangentially are arranged on the inner side of the partitions. Thisresults in a sturdier construction.

According to yet another preferred embodiment, the distance in radialdirection between the wall and the filter varies; during rotation thisresults in pressure variations on the ceramic filter, whereby the actionthereof is improved.

Other attractive preferred embodiments are stated in the remainingclaims.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be elucidated hereinbelow with reference tothe annexed drawings, in which:

FIG. 1 shows a broken away, perspective view of an apparatus accordingto the invention;

FIG. 2 is a schematic, cross-sectional view of the apparatus shown inFIG. 1 by way of elucidation of the operation of the ceramic filter;

FIG. 3 shows a cross-sectional view corresponding with FIG. 2 duringdischarge of the heavy contaminants collected by the centrifuge; and

FIG. 4 shows a cross-sectional view along the line IV—IV in FIG. 1.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 shows an apparatus according to the present invention which ismounted on a plate. Mounted on the underside of plate 1 is a fixed,downward extending cylinder 2. The cylinder is closed on its undersideby a flange 3. An upper filter flange 4 is further fixed to cylinder 2,as is a lower filter flange 5. A cylindrical ceramic filter 6 isenclosed by the two filter flanges 4, 5.

A control rod 7 further extends through the centre of the fixed innercylinder 2. Control rod 7 is mounted at its top side in plate 1 and ismounted at its bottom side in flange 3. The central control rod 7 ismovable in vertical direction but is held in its upper position by meansof a helical spring 8 and a disc 9 placed fixedly on control rod 7.

For supply to the interior of the drum use is made of a feed conduit 10.This latter, which is supplied by a pump so as to be able to develop therequired pressure for the ceramic filter, leads through the wall of thefixed inner cylinder 2, downward through fixed inner cylinder 2, andfinally debouches under the filter in the inner cylinder.

Use is made for draining the filtered liquid of a drain conduit 11 whichbegins on the inside of the ceramic filter, extends through fixed innercylinder 2 into the interior of this cylinder, and subsequently extendsonce again through this cylinder 2 to the outside.

The apparatus otherwise comprises a fixed bearing 12, which is formedfor instance by a rolling bearing, on which is mounted a belt pulley 13.On the underside of belt pulley 13 is arranged an end wall of the drum,this being the end wall 14 with the larger diameter. Arranged on theoutside of this wall is a ring 15 which overlaps wall 14.

A second, or movable, bearing 16 is further arranged which is fixed tocontrol rod 7 and to the rotating part of which the second, or small,end wall 17 of the drum is fixed. As a result of the fact that controlrod 7 is movable in vertical direction, bearing 16 and the end wall 17mounted rotatably thereon is likewise movable in vertical direction.This is also the case for the conical drum jacket 18 which is mountedfixedly on the small end wall 17. It is noted here that the large endwall 14 is separate from cylinder jacket 18. Outward extending ears 19are arranged at regular distances on the top side of drum jacket 18. Onthe underside of ring 15 are arranged pins 20 which extend through ears19 and bring about a tangential and radial fixation of ring 15 relativeto drum jacket 18 while still allowing an axial displacement of bothelements.

Walls 21 extending radially inward are arranged in drum 18. These arefixedly connected to drum jacket 18. On the underside of the large endwall 14 at the position of radial walls 21 are arranged cushions 28manufactured from resilient sealing material which provide a goodsealing. Radial walls 21 are further connected on their inner side by anarched wall 22 extending substantially in tangential direction.

The operation of the apparatus according to the invention will now bedescribed.

As stated, belt pulley 13 is driven in rotation by means of a drivedevice not shown in the drawing, for instance an electric motor, whichis connected by means of drive belts, likewise not shown in the drawing,to belt pulley 13. The elements connected thereto, i.e. the large endwall 14 and ring 15, are thus also driven in rotation. This is also thecase for pins 20, ears 19 and therefore drum jacket 18 and the small endwall 17 and the elements fixedly connected thereto and situated in theinterior of the drum, such as radial walls 21 and the tangential archedwall 22.

Liquid for cleaning is supplied via feed conduit 10 by means of a pump,likewise not shown in the drawing. This liquid enters the space betweenradial walls 21 and is carried along in rotation therewith. As a resultof the centrifugal force the liquid will collect in the vicinity of thelargest radius of the drum, i.e. in the proximity of the dividing linebetween the large end wall 14 and drum jacket 18.

When sufficient liquid is present, the whole space in the interior ofthe drum will be filled with liquid. As a consequence of said force, theheavy components of the liquid will collect in the proximity of thedividing line between the large end wall 14 and drum jacket 18, whilethe lighter components will collect further towards the inside, i.e. inthe vicinity of the filter 6 which is otherwise stationary. Theseelements are pressed through ceramic filter 6 by the pumping action,wherein the contaminants remain behind and the cleaned liquid is pressedthrough the filter and drained via drainage conduit 11. The contaminantsherein remain behind on the filter surface.

As a consequence of the fact that the liquid rotates because it iscarried along by the drum and the elements present therein, thecontaminants will adhere only with difficulty to the filter. The dangerof filter blockage is hereby reduced. This effect is reinforced stillfurther by the fact that the tangential wall 22 is arched. A pressuregradient changing rapidly in time is hereby created which likewiseprevents adhesion of the contaminants to the filter.

It will be apparent that both types of contaminant, that is thecontaminants with a higher specific gravity and the contaminants withlarger molecular dimensions, will remain behind in the drum.

Both types of contaminant will periodically have to be removed; thosefrom the filter by generating a counterflow in the usual manner eitherwith a valve system or by applying a separate pump, and those from thecentrifuge by moving control rod 7 downward by means of disc 9 andtherewith drum jacket 18 and the elements connected fixedly thereto. Agap is hereby created between drum jacket 18 and the large end wall 14which can be used to discharge the heavy contaminants. In order toactually obtain a discharging action, it is important that the drum thenrotates.

It is of course attractive to have these two cleaning operations takeplace perhaps simultaneously or, if this is technically impossible, inrapid succession. The normal cleaning process need then only beinterrupted once. However, this is a consideration which depends mainlyon the dimensioning of the diverse components and the nature of thecontaminants.

I claim:
 1. Apparatus for cleaning contaminated fluids, comprising acombination of a centrifuge for removal from the contaminated liquid ofcontaminants with a specific gravity other than the liquid and a filter(6) for removal from the liquid of contaminants which have moleculeswith larger dimensions than the liquid molecules, the combination beingintegrated in the apparatus, the apparatus comprising: a drum (14, 15,17, 18) drivable in rotation, having a conical jacket wall (18), largediameter end wall (14, 15) and small diameter end wall (17), said jacketwall being fixedly attached to said small diameter end wall; supplymeans (10) for carrying the contaminated liquid into the interior of thedrum (14, 15, 17, 18), the supply means comprising a pump for developingthe pressure required for the ceramic filter; discharge means (15, 19,20) for discharging the heavy contaminants from the part of the drum(14, 15, 17, 18) in the proximity of the large diameter end wall; an atleast substantially cylindrical ceramic filter (6) received in the coreof the drum; and drainage means (11) for draining the cleaned liquid,characterized in that the rotating jacket wall (18) is mounted on afixedly arranged core (2, 4, 5), the ceramic filter (6) is received inthe core (2, 4, 5), and the drainage means are arranged in the fixedcore (2, 4, 5,).
 2. Apparatus as claimed in claim 1, characterized inthat the discharge means comprise a moving device (7, 19, 20) forcausing the drum jacket (18) and the end wall with the smaller diameter(17) to move away from the end wall (14, 15).
 3. Apparatus as claimed inclaim 2, characterized in that the small diameter end wall (17) ismounted on a central, stationary shaft (7) which is drivable in itslengthwise direction, and that the drum jacket (18) and the large endwall (14, 15) are mutually connected by a connection (19, 20) allowingof a relative axial movement between said large end wall and saidjacket.
 4. Apparatus as claimed in claim 1, characterized in thatradially extending partitions (21) connected to the jacket (18) arearranged in the drum.
 5. Apparatus as claimed in claim 4, characterizedin that walls (22) extending substantially tangentially are arranged onthe inner side of the partitions (21).
 6. Apparatus as claimed in claim5, characterized in that the walls (22) are arched to provide variabledistance in the radial direction between the walls (22) and the filter(6).
 7. Apparatus as claimed in claim 2, characterized in that radiallyextending partitions (21) connected to the jacket (18) are arranged inthe drum.
 8. Apparatus as claimed in claim 3, characterized in thatradially extending partitions (21) connected to the jacket (18) arearranged in the drum.
 9. Apparatus as claimed in claim 8, characterizedin that walls (22) extending substantially tangentially are arranged onthe inner side of the partitions (21).
 10. Apparatus as claimed in claim7, characterized in that walls (22) extending substantially tangentiallyare arranged on the inner side of the partitions (21).